1. Field of the Invention
This invention relates generally to exercise machines of the class having one or more exercise members connected by a cable system to a weight, such as a variable weight stack, and each movable by a user of the machine along a certain exercise path to perform an exercise routine against the resisting force of the weight. The invention relates more particularly to an exercise machine of this class wherein the position of each exercise member along its exercise path at which the resisting force of the weight commences to act on the member, and hence also the portion of the exercise path over which the resisting force acts on the member, are adustable in order to vary the exercise routine performed with each exercise member.
2. Prior Art
Stated in very general terms, a typical exercise machine of the class to which this invention pertains comprises a frame having one or more exercise stations, a weight, typically a variable weight stack, movable up and down relative to the frame, an exercise member at each exercise station to grasped by a user of the machine and moved relative to the frame in a back and forth exercise motion along a certain exercise path, and a cable system connecting the weight and exercise member(s). This cable system is arranged in such a way that during movement of any exercise member in one direction along its exercise path, a lifting force is transmitted from the member to the weight which raises the weight from a normal lower rest position. During movement of the exercise member in the opposite direction along its exercise path, the weight returns downwardly to its rest position by gravity. The gravitational force on the weight is transmitted through the cable system back to the exercise member to produce on the member a resisting force which resists the exercise motion of the member.
The cable systems used in such exercise machines vary substantially from one machine to another. All of the cable systems, however, have the one common feature of a cable or cables through which the lifting and resistance forces are transmitted between the exercise member(s) and the weight and cable guides or pulleys on the machine frame around which the cable passes. During movement of any exercise member in its exercise motion, the lifting and resistance forces transmitted through the cable system between the exercise member and the weight stress the cable(s) of the cable system in tension.
The prior art is replete with a vast assortment of exercise machines of the general class described. Examples of such machines are found in U.S. Pat. Nos. 4,169,626, 4,199,139, 4,358,108, 4,390,179, 4,456,246, 4,505,475, 4,564,193, 4,634,127, 4,844,456, Great Britian 2,106,339 and West German 3,205,581.